NURSING DIAGNOSIS (hypokalemia)-help?

Can somebody help me please?i am having a hard time to decide what would be my nusring diagnosis for my client. her chief complaint is palpitation, and based on her lab results, she had low potassium. So, what would be the best nursing diagnosis you can suggest.please???i am having a hard time already.):
in addition, her health history was hypertension and DM II. please.i need your help.tnx.God bless!^^::wink2: